Outbreaks of bird flu, dengue fever and now the ‘brain-eating’ Naegleria fowleri have all made people very concerned about their health, but this brain infection, caused by the amoeba Naegleria entering through the nose, can be avoided.
This was the consensus of experts who spoke at a public health awareness programme organised by Aga Khan University Hospital (AKUH) on Thursday.
They advised the people to keep their head out of the water while swimming and prevent water going up the nose during showering and bathing.
Moreover, experts recommended the use of only boiled or chlorinated water when cleaning the nose for religious practices or other reasons.
“A person cannot get an infection from drinking or bathing in contaminated water. Nor does the infection spread through person-to-person contact.”
Speaking to the audience, Dr Syed Faisal Mahmood, consultant infectious diseases, said Naegleria causes a very rare form of brain infection, primary amoebic meningoencephalitis (PAM) that leads to the destruction of brain tissue and brain swelling.
Initial symptoms of PAM include headache, fever, anorexia, vomiting and later progress to a stiff neck, altered mental status, seizures and coma.
“Unfortunately, PAM is a fatal disease for which no effective treatment exists anywhere in the world. While amoeba-killing medicines are always given to patients, these usually do not work and death occurs almost 99 percent of the time. Only a small number of Naegleria cases have been reported worldwide, with a dramatic increase in Karachi recently,” he said.
Dr Afia Zafar, consultant clinical microbiologist, said Naegleria was commonly found in warm freshwaters such as lakes, ponds, rivers, hot springs and soil.
It is a heat-loving microbe which multiplies well at temperature from 28°C to 40°C and tolerates up to 45°C. It is less likely to be found in water as temperature declines. Naegleria is not found in salt water, such as sea water.
“In developed world where domestic water supply is safe, most victims are children as they expose themselves to unclean water in lakes and rivers during water related recreational activities. In Karachi, unfortunately, due to compromised chlorination of domestic water supply, the disease is not limited to children and many healthy males between the ages of 16 and 42 years are contracting it,” she said.
Dr Zafar advised the public to clean overhead and underground water tanks twice a year and fill with chlorinated water (0.5ppm of residual chlorine is required at domestic level that can be increased up to 1ppm if water looks turbid). He also advised them to only swim in well-maintained and properly chlorinated swimming pools, not to allow children to play with hoses or sprinklers as they may accidentally squirt water up their noses, and not to jump or duck dive into warm fresh water without closing the nose or using the nose clip.